The inventors of the present application proposed a semi-automated pig thigh de-boning apparatus and method of de-boning pig thigh using the apparatus in Japanese Laid-Open Patent Application No. 2000-106818 (patent literature 1). In the de-boning apparatus, preprocessing, lower thigh bone removing operation, and thigh bone removing operation are carried out while the ankle part of a pig thigh is held by a damper attached to a transfer chain and transferred in a hanged state through each station.
In the fully automated step succeeding the preprocessing step of the de-boning apparatus, the pig thigh (work) hanging from the damper is made incision around the lower thigh and thigh with a cutter while scraping off the meat adhering to the bones with a meat separator. By this, biological tissue such as meat, muscle, and tendons adhering to the bones is cut, and meat is separated from the bones step by step. These incisions are made at determined positions in longitudinal direction of the bones by rotating the work.
Further, the inventors also proposed a de-boning apparatus arm part meat block and shoulder butt of a slaughtered animal in W2004-068953 (patent literature 2). In this apparatus, preprocessing of removing shoulder butt, spareribs, and lower forelimb bones is done, and then incision is made around the upper forelimb bone and shoulder blade. Like this, preprocessing is performed to the maximum extent and then automatic de-boning is limited to the minimum necessary extent, that is, only removing of shoulder blade and upper forelimb bone is automated. This apparatus is suitable to middle to small scaled meat processing factories featured in space-saving and cost-saving.